This invention relates, in general to custom molded orthopedic braces, and more particularly, relates to methods and apparatus for the formation of a custom molded impression of a patient""s wrist area which can be used to form an immobilization cast or wrist brace.
Custom casting of a patient""s wrist area can be employed to effect relatively complete immobilization of the wrist, for example, to heal a broken bone, or merely to limit wrist motion, for example, to treat carpal tunnel syndrome or to prevent over-extension of the wrist while performing various tasks. Motocross motorcycle riders, for example, are at risk for painful wrist injuries as a result of dynamic shock loads which can over-extend the wrist, pulling or tearing ligaments and tendons. A removable custom molded wrist brace which permits limited motion and yet will resist extreme wrist articulation under dynamic loading would be highly desirable for such activities.
As used herein, the expression xe2x80x9cwrist areaxe2x80x9d shall be understood to include the area extending from a patient""s forearm across the wrist to a position over the patient""s hand.
Considerable effort has been directed toward the formation of orthopedic immobilizing casts or braces for various portions of patients"" anatomies, most usually limbs. To the extent that immobilizing casts or braces are formed for limbs, the cast and/or brace must be sufficiently rigid to support and/or immobilize the portion of the patient to which the cast is applied. This, in turn, usually requires that casts or braces be formed of a multiplicity of layers of material to provide the necessary strength and rigidity for immobilization.
Typical of the prior art multi-layered immobilization casting systems are the orthopedic casts shown in U.S. Pat. Nos. 5,514,080; 4,683,877; 4,129,127; 4,019,506; and 3,656,475. Since these systems employ multiple layers and various combinations of hardening materials, they are tedious and difficult to form on the patient in order to achieve the highly desirable custom fit. Such custom casting, it will be understood, is often undertaken when the patient is in pain or experiencing considerable discomfort, making the construction of a cast in situ a disagreeable experience.
Moreover, part of a casting process often requires that at least a portion of the patient be held or maintained in a desired position during casting so that the eventual cast will support the patient as needed. As the casting time becomes longer due to the complexity of forming a cast with sufficient rigidity to support the patient, it is more difficult to maintain the desired patient orientation or positioning. Since in situ casting is often accomplished using resins which produce considerable heat during rigidification, another problem is providing sufficient thermal insulation between the patient and the various casting layers, which can contain a substantial volume of resin. Many casting resins experience exothermic curing. The thermal insulation required to withstand exothermic resin curing again makes the process of in situ casting more complex and tedious, as well as interposing layers between the patient and the eventual rigid cast which can affect cast fit.
Less has been done in the area of custom molded braces which permit some motion but provide the user with support which will avoid further injury (carpal tunnel syndrome) or which prevent injury to the wrist from over-extension. Such braces are desirably light in weight and removable for ease of use.
One wrist area custom molded cast system in which the cast can be selectively mounted to the patient""s wrist and removed is being commercially exploited by Distrac Ortho-Medical Supplies of Hoegaarden, Belgium, under the trademark ZIP-Y-CAST. The ZIP-Y-CAST system is mounted from the side of the arm to the patient""s wrist area and which includes a resin molded cast which incorporates a zipper or VELCRO hook and loop fastener structure to close the longitudinally extending, open side of the cast. The molding system, however, is messy in its use, requiring the pouring of the hardening resin between two fabric sleeves and thereafter dispersing of the resin evenly throughout the casting fabrics before hardening using a roller.
Accordingly, it is an object of the present invention to provide a custom molded wrist impression kit and method that can be used to mold an impression of a patient""s wrist area which can be used as a custom, rigid, immobilizing brace as a removable, motion-limiting, support brace.
A further object of the present invention is to provide a method of forming a custom molded wrist area impression kit which is suitable for home use as well as use by medical technicians.
A further object of the present invention is to provide a kit for and a method of forming, a custom molded wrist area impression cast that can be easily removed and remounted to the patient""s wrist area and has sufficient flexure for limited hand motion and sufficient rigidity to resist wrist over-extension.
Still a further object of the present invention is to provide a custom molded wrist area impression cast and method which are suitable for scanning to enable the subsequent formation of an immobilizing wrist cast.
Still a further object of the present invention is to provide a custom molded wrist are impression cast and method for formation of the same, which is easily removed after casting, can include a cushioning layer, and can be selectively cast to be relatively rigid or relatively flexible, depending upon its use.
The custom molded wrist are impression kit and method of the present invention have other objects and features of advantage which will become apparent from, or are set forth in more detail in, the accompanying drawing and the following description of the Best Mode of Carrying out the Invention.
The custom molded wrist area impression kit of the present invention comprises, briefly, an elongated tubular fabric impression sleeve having a configuration substantially covering the wrist area of a patient and a thumb-receiving opening therein. The sleeve has sufficient elasticity to enable mounting over the patient""s hand onto the wrist area and thereafter to conform to the patient""s wrist area. The kit also includes a quantity of curable resin, preferably impregnated in the impression sleeve, sufficient to rigidify the impression sleeve. Most preferably the impression sleeve includes a weakened strip extending longitudinally from one end to the other to facilitate severing of the hardened sleeve and its removal after casting. A second weakened strip on an opposite side of the cast can provide a line hinge for articulation of the hardened sleeve to permit its removal and remounting.
The method of forming a custom molded wrist area impression brace of the present invention comprises, briefly, the step of mounting a tubular, elastic, hardenable, impervious sleeve over a patient""s hand to a position across the wrist area, manipulating the wrist area to a desired orientation, and hardening a resin in the impression sleeve while the patient""s wrist area is in the desired orientation.
The present method further preferably includes the step of removing the hardened impression sleeve by cutting the hardened impression sleeve along a weakened strip in a side of the impression sleeve and resiliently outwardly displacing the cut hardened impression sleeve, preferably about a second weakened strip on an opposite side of the impression sleeve.